1. Field of the Invention
The present disclosure relates to percutaneous catheters, more particularly, to percutaneous catheters having a changeable working length.
2. Description of the Related Art
One of the differences with the use of peripheral percutaneous transluminal angioplasty (PTA) catheters compared to percutaneous transluminal coronary angioplasty catheters (PTCA) is the ubiquitous need for different working lengths for PTA catheters. Coronary catheters are designed to traverse a fixed distance between the access point (common femoral, brachial or radial artery) and the heart (or sometimes the brain) to treat lesions. Thus, a single standard PTCA catheter length of 135 cm satisfies almost all the distances needed to treat these lesions irrespective of the patient height and habitus, while at the same time not having too much redundant catheter outside the body. In difference, the target lesions for PTA vary in location and distance from the access site so a single catheter length, if too short, will not reach all the lesions and, if too long, will leave a long unwieldy segment outside the body that is difficult to keep in the sterile field.
For example, PTA catheters may be used to treat lesions very close to the access site with an ipsilateral iliac approach where the distance from the sheath in the common femoral artery to the lesion may be only 5 to 20 cm. Compare this to the patients with lesions in the great vessels like the subclavian artery where the target treatment sites are frequently over 100 cm remote from the femoral access site.
A problem arises when using too long of a catheter in the short distances because the length requires guide wires two times the catheter length, and these often extend below the patient's feet while on the interventional table, and the devices become clumsier and can take two people to load and unload the catheter on the wire. This also creates an increased risk for catheter contamination as the proximal end of the catheter can flip up and hit an unsterile monitor or even reach the floor. In these instances the entire system must be discarded and the procedure begins all over again. Hence, there is a preference for shorter catheters when the target lesion is close to the access site, and for longer catheters when treating more distal lesions that cannot be reached by shorter catheters. Shorter catheters are simpler in the close proximity cases and require less labor and time under fluoroscopy (i.e. radiation exposure).
This need for different length catheters creates a burden on the end user in the hospital catheter lab to stock large amounts of inventory due to all the combinations of lengths and sizes. Catheters may be chosen by guide wire size (e.g., 0.014″, 0.018″, or 0.035″), balloon pressures/compliance (i.e. high pressure non-compliant, or low pressure compliant), over a range of balloon diameters and balloon lengths, and by whether the systems are balloon only or balloons with stents mounted on them. In the domain of PTA, the inventory is doubled by the need for 2 or more working lengths. This leads to thousands of units being stocked and accounted for in the hospital catheter lab, for example up to 3 wire sizes×2 pressure types×10 diameters×8 balloon lengths×2 catheter lengths, plus having multiples of each size available. Layered on top of this, the catheterization laboratory may need multiple product types from multiple suppliers since different products are needed for different lesions.
Recent changes in Joint Commission on the Accreditation of Healthcare Organizations (JCAHO) guidelines make it more difficult for hospitals to maintain inventory and protect products from contamination. Many hospitals have shifted to closed inventory management systems with limited space. In a typical hospital, about 60 percent of the total supply cost is driven by three clinical service areas: surgery, cardiology and pharmacy (source: 2004 VHA Supply Cost Benchmarking Database; VHA, Inc.). Forty percent of supply costs can be attributed to implants, stents, and other devices (source: Serb, Chris; Strategic Savings; Hospitalconnect.com; Apr. 16, 2004). Add to this that many hospitals are pushing companies to provide products on consignment, then additional costs are also funneled back to the companies that manufacture the product.